Some current web services rely on content delivery networks (CDN) to distribute data from content providers (CPs) to end users. A CDN can be defined as a system of servers (referred to hereinafter as “content servers”) placed at various points in a data network (e.g. the Internet, an intranet, etc) and containing cached copies of certain data (as provided from the CPs) so as to improve access to the data from clients. In general, CDNs are configured to allow a client to access a copy of the data near to the client, as opposed to all clients accessing the same (i.e. central) content server. Caching of content in CDNs offers considerable advantages including load distribution and improved response times to clients.
A client can be, for example, user terminal equipment (UE) of a user connectable to a network system arranged to provide data connectivity access to end user equipment (UEs). A network system arranged to provide data connectivity access to end user equipment is referred to here as an Internet Protocol (IP) Connectivity Access Network, IP-CAN. One example of an IP-CAN is a 3GPP mobile telecommunication network system that facilitates data connectivity access to users of UEs, such as the network system of an operator providing a GPRS service, or any other kind of packet-switched based access network system. A CDN can comprise content servers that can also be located within the network domain of operators providing an IP-CAN; that is, a network operator providing an IP-CAN can also be a CDN operator.
Content susceptible to caching is generally of a static nature and is not user specific, and has some considerable size. Examples of content susceptible to caching include, for example, images, data files, video files and multimedia streams.
Content delivery and caching solutions available currently often rely on an explicit agreement between the CP and the CDN to select cacheable material. Subsequently, the material is distributed across servers of the CDN—in according with the agreements—and is kept updated therein. This implies storing and maintaining a considerable volume of data within the CDN caches. Furthermore, the current solutions make the setup and maintenance of a caching scheme expensive and difficult to implement, since it implies that caching and updating policies—as determined by the agreements between the CPs and CDN operators—has to be implemented by CDN servers. This can have a special significance for CDN operators having to deal with cached content belonging to a plurality of CPs.
Moreover, telecommunication operators that provide user terminals with access to data networks (e.g. GSM/GPRS/UMTS operators providing IP-CAN access) can face high transmission costs (i.e. peer costs) for fetching content that is cached in a CDN that can belong to the network domain of a different operator, especially where that CDN is located in a different geographical region. For example, a subscriber located within the Philippines may be accessing web information cached in California.